(1) Field of the Invention
The present invention relates to a deodorant composition capable of easily and efficiently removing an odor component containing a compound having a carbonyl group such as aldehydes and ketones, thereby achieving deodorization, a deodorizer and filter containing the same, and a method of deodorization using the same. The technique of the present invention is especially effective in removing the odor component from a room of car, house and building.
(2) Description of the Prior Art
At large equipment such as sewage treatment plants and thermal disposal plants in urban areas, odor components are removed from gases by use of sprinkler system cleaning device which uses washing water prepared by dissolving medicine reactive with odor components into water. At small and closed spaces such as toilets, rooms of houses and buildings, and rooms of vehicles, it is impossible to install a large-scale sprinkle system cleaning device. In these spaces, therefore, odor components are usually removed by use of physical adsorbents such as an activated charcoal.
It is confirmed that, in an inter space of a vehicle such as a car, there are odor compound having a carbonyl group such as formaldehyde acetaldehyde, acrolein, and benzaldehyde, as malodorous components generated from decomposed gases of fuels and oils, combustion products from cigarettes, adhesives used for adhesion of interior boards and interior parts of vehicles, and heat insulating foamed resins. In rooms of houses and buildings, there are malodorous components of the same types as those in the vehicle evaporated from heat insulating materials, plywood, and adhesives, and derived from combustion products from cigarettes. In a conventionally known method, these odor components are adsorbed and removed by mounting a member filled with an activated charcoal to an air-cleaner in the room.
The present inventors have found that a physical adsorbent such as an activated charcoal has the following problems. In one problem, although the physical adsorbent exhibits a relatively high ability of adsorbing and removing odor components if the components have high adsorptive property, it has almost no ability of adsorbing and removing a carbonyl group-containing compound. The other problem of the physical adsorbent is as follows. The physical adsorbent such as an activated charcoal conducts deodorization by capturing the odor components into its adsorption sites. When the adsorption sites are saturated with the odor components, the odor components cannot be adsorbed any more. At the same time, the physical adsorbent also adsorbs moisture (i.e. water) In the gas together with the odor components. If the adsorption sites are saturated with the moisture, the odor components cannot be adsorbed any more. The air in the rooms of houses, buildings, and cars contains a large amount of moisture. When used in such rooms, the physical adsorbent adsorbs the moisture and is saturated in a very short time, and as a result, loses its ability of adsorbing odor components.
Japanese Laid Open Patent Publication No. Hei 9-313828 discloses a filter for cleaning the air by removing aldehyde therefrom. The filter is formed with a carrier such as an activated charcoal for carrying a medicine for removing aldehyde. However the medicine is an amine or ammonia compound, and has the problems in use because the medicine itself smells, generates acidic ions which are highly corrosive, or sublimates. Specifically, the following compounds are disclosed as the medicine, but have disadvantages as follows. Triethanolamine, pyrdine, and hexamethylenetetramine have irritating smell like ammonia at a room temperature. Casein, casein sodium, and glycine gives out odor at a room temperature. Urea and thiourea smells bad at a high temperature (80 to 100.degree. C.), and the smell becomes stronger in the presence of moisture. Amine or ammonia salts, also disclosed in the prior art application, have no problem of odor; however, they dissociate by moisture to generate highly corrosive ions (such as ammonium sulfate, and ethylene diamine tetraacetic acid (EDTA).multidot.2Na), liberates acids (such as polyallylamine hydrochloride, aminoguadinine sulfate, guadinine nitrate, and hydroxylamine sulfate). Due to these disadvantages, the amine or ammonia salts can be used in only limited applications. Dimethylhydantoin has no problem of odor and corrosion; however, it sublimates and is not suitable for a deodorant. In the technique disclosed in the prior art application, the medicine for removing aldehyde itself has problems of odor and corrosion.